Previous reports of biodiversity loss, whilst very serious, have focussed exclusively on species extinctions, ignoring the wider scope of global population declines and ‘range shrinkages’ of both endangered and common species. The authors – amongst them Paul Ehrlich, best known for his controversially alarmist predictions in the 1968 Population Bomb – argued that this bigger picture justified the escalation of rhetoric. Scientists ought to convey not a gradualist decline of life, but “biological annihilation” and a “frightening assault on the foundations of human civilisation”. The lead author claimed that “the situation has become so bad it would not be ethical not to use strong language.”

The report concludes, in essence, that the devil is in the detail. Specifically, the numerical detail. Up to half of all individual animals have been lost in recent decades. The ranges of a third of all vertebrate species have radically shrunk (PNAS). But more interestingly, the report might be interpreted as saying, the numbers ought to do more political and moral work than they currently do. And we are right to consider ways of engaging the public with those numbers on more than scientific grounds. Clearly, the authors think that the numbers have the power to shock us out of a kind of numbness and apathy about a catastrophic moment in Earth’s history. But they implicitly know that the numbers don’t speak for themselves.

It is pertinent to consider the combination of numerical symbolism and moral discourse in ancient Jewish and Christian apocalyptic literature in this light. Of course, the ultimate picture painted there is a cosmic eschatological drama – very much the end of the “foundations of human civilization” as we know it, but also the birth of a new one. But in the Christian book of Revelation, chapter 8, vivid imagery of the decimation of both human and nonhuman populations also plays a central part in this transition. It takes part amidst a general dramatic rendering of the transformation of all the essential elements of the world (at least for a 1st-century audience): earth, rivers, sea and sky. At the sounding of the first trumpet, “a third of the earth was burned up, and a third of the trees were burned up, and all the green grass was burned up. The second angel sounded… and a third of the sea became blood, and a third of the creatures which were in the sea and had life, died.” (Revelation 8:7-9). In the following chapter, four angels release a plague that brings death for “a third of mankind” through fire and brimstone.

What is the significance of this numerical specificity? Is there an underlying moral function that parallels the rhetoric of extinction reporting – an attempt to shock us out of apathy? An eco-theological perspective might think of it as a warning about the irreversible harm to creation brought about as a result of wickedness (consider the later phrase “the Lord destroys the destroyers of the Earth”, Revelation 11:8). Christian Climate Change Organisations like Operation Noah have used Revelation in a more politically galvanizing way: apocalyptic warnings are as much calls to repentance than the dishing out of punishments. At the other end of the spectrum, literalist readings of apocalypse – for instance dispensationalist websites such as Rapture Ready or the Hal Lindsey Report – have become recently interested in extinction reporting as further evidence of the nearness of end-times. Although these last would insist that these are curses wrought by God, not anthropogenic global warming or population increase. Still, they confirm in a very specific way that the power of numbers can take on more than scientific significance.

There are, of course, several different exegetical interpretations of the significance of ‘one third’. Does it signify the fact that one third is only a portion, reminding us that there is more tribulation to come? Or that the rate of decimation is increasing, up from the ‘one fourth’ of the earth subjected to destruction under the hand of the ‘pale rider’ (Rev 6:8)? Or, more hopefully, that not all life is destroyed – there is still something to preserve in creation, and all the more reason to act more justly in order to do so? Perhaps a more nuanced view is that the audience of apocalypse is reminded that what is revealed (apokalyptein, to disclose) is a mystery to normal human understanding, and demand greater wisdom as well as humility – an awareness that humanity is not in control of its own destiny as it once thought it was. Just as with numerical prophecy of the end-times, so with numerical representation of beings, living and the dead. The symbolic use of numbers can act powerfully upon the imagination, but seem to be most powerful of all when placed within a bigger moral narrative.